Development and applications of DifferentialGeometry are supported in part by National Science Foundation grants OCI-1148331, DMS-071380, DMS-0410373.
GR 20 Workshop, Warsaw, July 2013, Ian M. Anderson and Charles G. Torre
The Spacetime Geometry of an Electromagnetic Wave, Charles G. Torre
The Spacetime Geometry of a Null Electromagnetic Field, Charles G. Torre
New symbolic tools for differential geometry, gravitation, and field theory, Ian Anderson and Charles Torre; Journal of Mathematical Physics